Mysterious Fog That 'Smells Like Chemicals'- Natural Phenomenon Or Cause For Concern?`

Image Credit: Canva (representational only)

Updated Jan 10, 2025 | 02:00 AM IST

Verified By

Mysterious Fog That 'Smells Like Chemicals'- Natural Phenomenon Or Cause For Concern?

SummaryFog often traps pollutants like sulfur oxides and nitrogen oxides, amplifying chemical odors in the air. The high humidity allows these particles to linger, potentially irritating respiratory systems and causing health concerns.

A heavy fog that "smells like chemicals" has been covering several parts of the United States lately, raising health concerns for people exposed to it. Reports have described sore throats and coughing, fatigue, and eye irritation among the exposed. But why does this fog smell so weird, and why are some people falling ill?

In this article, we will explore the science behind this phenomenon, how fog forms, and why it might sometimes carry chemical odors that linger in the air. By the end, we will also debunk some of the more speculative claims that have surfaced in the wake of this mysterious fog event.

The ‘Chemical Fog’ and Its Health Impacts

The fog has started trending on social media, with multiple users saying that it smells of fireworks, chemicals, or even sewage. David Bamber of St. Petersburg, Florida, shared a very popular TikTok video describing the sensation of walking through the fog and having the feeling of inhaling something toxic. Others reported developing respiratory conditions, including sore throats, coughs, and general fatigue, which they blamed directly on the fog. In fact, a Florida resident described how, following a short detour at a gas station, she started sneezing uncontrollably and became feverish, with stomach cramps as well. For some, this "sickness-fog" has become an urgent health issue.

As alarming as this is, the mist might not seem so evil. After all, there are scientifically established reasons about how fog functions with its surroundings, especially relating to pollutants, which could strengthen the odor it has.

Fog Formation and Its Chemical Absorption

This takes place when the water vapor present in the air condenses to become small water droplets and eventually form a low-lying cloud, making visibility hard to perceive. Such droplets will act as natural scavengers absorbing all airborne pollutants and particles. Moisture contained within the fog will amplify the concentration of pollutants such as chemicals and odors to make them much stronger and hence easily noticed.

According to Washington University atmospheric scientist Professor Rudolf Husar, chemicals trapped within the fog droplets "include sulfur oxides and nitrogen oxides, gases primarily produced by industrial activity, vehicle emissions, and, more rarely, natural fires. Those chemicals stay in the air a long time, especially because when they are trapped in these droplets, they become concentrated and kindle chemicals and odors in the surrounding environment.". This process is known as "scavenging," where fog droplets absorb gases and pollutants, allowing them to linger longer than they might in clearer air.

Also Read: Health Concerns Rise As US, Canada, and UK Come Under The Blanket Of Thick, Dense, Toxic Fog

The reason why this fog smells so potently is that humidity increases the way smells move. When water molecules in the air combine with odor-causing molecules, they tend to last longer and thus become more pronounced to our noses. This explains why some people have reported that the fog smells like chemicals or even like sewage, depending on the surrounding environment's air quality.

What Role Does Atmospheric Conditions and Pollutants Play?

More than just an atmospheric visual appearance, fog could often trap most kinds of pollutants when the ground-adjacent layers are extremely cold, often experienced during the cold season. As it douses many inhabited spaces, pollution is able to cling with the fog through smokes emitted from vehicles, factory chemicals, among other things. When people inhale this "chemical fog," they may feel irritation in the respiratory system. It is particularly more sensitive to individuals with pre-existing conditions, like asthma, who have airways that are easily irritated by a change in air quality.

In addition, air pollution generally causes a variety of health issues, from simple coughing and congestion to severe respiratory problems. The moisture of the fog increases these effects, introducing more water into the lungs and causing irritation. This is why some people may feel shortness of breath, chest pain, or even experience wheezing when exposed to dense, polluted fog.

Fogs often occur where, for instance, Florida regions do, following a specific set of weather, often temperature inversion. In cases of temperature inversions, there will be cooler air trapped very close to Earth by warmer air over it so that pollutants from whatever source have less space to dispel into the atmosphere. That accumulated pollutant within the fog contributes to having that chemical even more pungent.

Besides pollution, local moisture sources heavily influence fog. For example, areas next to large bodies of water like the San Francisco Bay often see thick fog in summer months as the water chills the surrounding air. However, in some areas, fog can form where moisture from the ground is evaporating into the air, condensing, and forming thick fog near the surface. Moisture, once condensed, can absorb pollutants and enhance existing odors.

Is There a Conspiracy Behind the Fog?

As the fog event has continued, some people have begun to speculate that there might be a more sinister or secretive explanation for the phenomenon. Conspiracy theories have been circulated, suggesting that the fog could be the result of a chemical weapon or even a government experiment. Such claims have largely been fueled by comparisons to Operation Sea Spray, a controversial U.S. The Navy biological warfare experiment in the 1950s where bacteria were released in the San Francisco Bay area to test the city's vulnerability to biowarfare.

Also Read: When Fear Clouds Judgment- The Psychology Behind The Mysterious Fog Over US And Canada

Even if the thought of a planned chemical fog, produced by humans, is quite threatening, science cannot prove such an idea. In fact, according to experts, the cause for the fog may simply be a part of the regular weather, in combination with higher concentrations of pollutants from human sources. Chemicals in the air, specifically sulfur and nitrogen compounds, are nothing but by-products of industrial pollution, not some sort of deliberate attack.

Why Does Fog Smell Like Chemicals?

In summary, the chemical-like odor produced by fog is a result of various environmental and atmospheric conditions. Due to fog's natural collecting characteristic, pollutants are trapped inside the fog droplets, which are very small in size. Thus, these pollutants include sulfur and nitrogen oxides, which are usually derived from vehicle emissions, industrial processes, and even wildfire cases. The moisture in the fog makes these odors more observable and potent.

Fog is not dangerous in itself, but the pollutants it captures can cause irritation to the respiratory system, especially for people who have pre-existing health conditions. Knowing how fog forms and how it interacts with its surroundings will help us prepare better for the effects of fog and address health concerns that may be triggered.

Even if this recent bout of fog caused concern, there's scientific logic for why this situation is not to be worried about. Nonetheless, being cognizant and knowing the quality of air is also a form of mitigation from this thick chemical smell fog that affects health.

End of Article